The problem of obtaining accurate foot measurements has existed since man first started to wear shoes. Many devices of varying degrees of complexity have been proposed over the years for providing two-dimensional measurements of length and width of the human foot in order to provide appropriately fitted shoes and insoles. Representative of such devices is that of Charles Brannock, disclosed in U.S. Pat. No. 1,725,334. Brannock's device, familiar to anyone who has ever visited a shoe store, basically consists of two slides mounted on an indexed base plate to determine the length and width of the foot.
Since Brannock's day the technology has improved, providing pressure sensors and light sensitive sensors of various types to measure the length and the width of the foot. In U.S. Pat. No. 5,659,395 is presented a system that improves somewhat on the existing foot measurement systems. The system disclosed in this patent utilizes a combination of a pressure pad assembly for each foot surrounded by a linear array of infrared light emitting diodes (LEDs) located around the perimeter on two sides of each pressure pad and two corresponding arrays of phototransistors acting as detectors on the opposing sides. The length and width measurements are determined by combining information provided by the pressure pad with the data from the infrared arrays indicating which of the optical paths are blocked by the foot placed between the emitters and the receivers. The apparatus in U.S. Pat. No. 5,659,395 additionally has matrices of emitters and corresponding detectors to give height information at selected locations along the perimeter of the foot. However, U.S. Pat. No. 5,659,395 possess several significant disadvantages. First, the relatively large size and complexity of the apparatus makes it an expensive device, which may be prone to malfunction. Second, the accuracy of the measurements is limited by the size of the LEDs, because if a foot ends between two emitters, the reading will determine the size according to the last optical path blocked, with no consideration of in-between cases. Additionally, in order to reduce errors due to outside light sources, the apparatus applies modulated current to the emitters and modulation filters to detect the modulated signals. This introduces a significant amount of components and complexity to the electronic circuitry.
U.S. Pat. No. 7,336,377 to the applicant of the present application describes a foot measuring device for the determination of foot dimensions. The device comprises two emitter/detector pairs and two pressure pads assemblies. The feet are measured by the use of a mechanical arrangement, which enables the emitter and detector of each pair to be moved in parallel along two pairs of rails that are oriented in mutually orthogonal directions. Finally, the data obtained is stored, analyzed and displayed.
The field of retail shoe stores is an intensely competitive one in which each store owner must be able to provide a high level of service in order to achieve and maintain his share of the market. Part of providing such service would be to make available to his customers a system, for measuring their feet and using these measurements to supply good fitting shoes. In order to be able to provide this service, the measuring apparatus must be durable, reliable, and easy to operate; must provide accurate, easy to interpret results; and must be relatively inexpensive to purchase and operate.
It is a purpose of the present invention to provide an apparatus for measuring the length and width of the human foot.
It is another purpose of the present invention to provide an apparatus for measuring the length and width of a human foot that does not contain motors and moving parts, and that is easy to operate.
It is still another purpose of the present invention to provide an apparatus for measuring the length and width of a human foot with a high degree of accuracy.
It is yet another purpose of the present invention to provide an apparatus for measuring the length and width of a human foot that is relatively inexpensive to purchase and to operate.
It is still another purpose of the present invention to provide a method for calculating the exact length and width of a human foot in case that the foot was placed improperly in the measuring apparatus.
Further purposes and advantages of this invention will appear as the description proceeds.